Costs can vary widely due to factors such as demand, the method of and the timing of making the booking.

And research from the Airlines Reporting Corporation (ARC) indicates that Sunday bookings have been cheaper than on other days of the week for five years in a row.

Mario Van Poppel, CEO of leading currency exchange firm Manor FX, said: “We all know that the cost of flights fluctuate greatly and it can be difficult to know how and when to search to get the best deal.

“Two different people booking the exact same flight can pay up to hundreds of pounds more based on a range of factors, and timing is one of the most influential.

“Being organised often pays off when it comes to arranging trips, while leaving things to the last minute can see you paying over the odds.

“It’s interesting to see that booking on a Sunday may well be better than on other days of the week, and it could reap rewards to reserve flights while winding down for the weekend.

“There are a range of other ways to save money on trips abroad too, such as booking airport car parking in advance and exchanging your travel money before you go.”

Data from ARC, which manages transactions between U.S.-based travel agents and airlines, to see if specific days are cheaper for booking or flying.

They found that travelers booking on Sunday can save up to 13 percent on domestic and international flights compared to Fridays, which are often the most expensive day to buy.

Although the exact reason isn’t clear, it may be that people are more likely to book during the working week and see Sundays as a day to rest or spend time with family and friends.

The research also found Thursdays are the cheapest day to travel, saving around 16 percent compared to those departing on a Sunday.

And booking flights exactly 28 days before departure can also save travellers cash.

The data suggested fliers can save an average of 24 percent compared to booking further away or closer to the departure date.

Travelers can use additional cost-saving strategies, like pre-booking airport parking to save on fees, or opting for connecting flights, which are often cheaper than direct options.

And for getting your hands on travel currencies, it’s generally best to research the best rates and get cash for day-to-day spending before you go.

This is because foreign exchange bureaus and ATMs in other countries can leave you exposed to worse rates and fees.

Manor FX is one of the leading foreign currency exchange experts with more than 30 years of experience.